Books



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H. A. DEJSILVERA.

INDEXING BOOKS.

.Paten ted Aug. 21, 1883.

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UNITED STATES PATENT Fries.

HERBERT nuns SILVEBA, on NEW YORK, n. x, nssIenoR or ONE-HALF roPOULTNEY BIGELOW, oFsAMn rnncn.

I INDEXING BOOKS.

SPECIFICATION forming part of Letters Patent No. 283,383, dated August21, 18 83.

- Application filed October 4, 18851. Model.)

To all whom it may concern.-

Be it known thatl, HERBERT A. DR SI'L- VERA, a citizen of the UnitedStates, residing in the city, county, and State of New York, haveinvented a certain new and useful Improvement in Indexing Books; and'Ido hereby declare'that the following is a full, clear, and exactdescription of the invention, which will enable others skilled in theart to which it appertains to make and use the same.

Herctofore books have been indexed by-applying to the leaves themselvesat particular intervals the characters used in guiding the search of thereader.

, To carry my invention into effect I cut into i the body of the leavesof the book concave niches. The said niches form two walls, on either ofwhich wall-surfaces characters may be impressed, which said indexcharacters may be seen from two points of view when the vol-.

ume lies open to the reader.

The advantage obtained by placing the index characters upon both wallsof the concave niche is from the fact that when the reader holds a heavyvolume before him provided with this system of indexing he can referbackward as well as forward without first altering the position of hisbook.

The improved form of indexing is calculated to be of especial service tothose who have occasion to consult dictionaries, directories, heavycounting-house volumes, ofi icial digests, records, &c,

A striking advantage of my process is, that the index charactersimpressed upon the concave walls of these index-niches may be made toappear either narrow or broad, according as the volume is pressed to oneside or the other by the hand applied to the back of the volume. In caseof a volume of moderate size this advantage becomes especiallyprominent. In consequence of this feature, incident to placingcharacters upon such concave wall, said concave space may be utilizedfor the purpose of placing upon its surface a larger number ofcharacters than could be conveniently placed upon the semicircularexposed white surface opposite. In order to take advantage of thispeculiarity in the action of segmental pages, the index characters areimpressed when the concave wall is expanded, so as to exhibit anunusually large exposed concave surface. Being impressed under suchconditions, the indexcharacters will appear unusually narrow when thevolume is closed, but of ordinary size when the volume lies open.

In the accompanying drawings, Figure I represents the left section ofthe book open to the reader. The numerals 100, 500, 1,000, &c., areplaced upon the concave walls of the niches above described, and vary insize according to the angle at which the book is opened.

Fig. II represents a closed volume with the index-niches exposed toview. The numerals I, II, III, IV, V, &c., are placed upon theconcavewalls, and are all visible at one time, whether the book lies onone cover or the other.

Having thus fully described my invention,

what I desire to claim, and secure by Letters Patent, is

A book having concave niches cut into the edges of its leaves, with theindex characters placed upon the concave walls of said niches,substantially as and for the purpose described.

H. A. DE SILVERA. Witnesses:

LUMAN W. JoHNsoN, AUsTIn E. PRESSINGER.

